Field of the Invention
The present invention relates to an operation apparatus, or more specifically, to an operation apparatus provided with a touch detection function, and to an image pickup apparatus and a personal digital assistant each including the operation apparatus.
Description of the Related Art
In a conventional information display and input apparatus including a so-called touch panel located on a display unit such as a liquid crystal panel, images of virtual buttons and so on are displayed on a display screen. In this state, a user can input or select information allocated to a certain one of the virtual buttons by touching an area on the touch panel corresponding to a display position of the certain virtual button with a fingertip, a pen tip of a stylus pen or the like. This touch panel has almost plane surface geometry, so that the user input relies on visual guidance. As a consequence, it is inherently difficult to input data accurately because adjacent buttons are not tactually distinguishable. Given the circumstances, there have been proposed user interfaces that can provide tactile guidance.
For example, Japanese Patent Application Laid-Open No. 2011-508935 discloses a user interface, which can provide a user with tactile guidance by inflating a void portion under a surface layer and thereby deforming a particular region of the surface.
However, the related art disclosed in Japanese Patent Application Laid-Open No. 2011-508935 does not take into account a tracing operation (a slide operation) on a touch panel area with the fingertip, the pen tip of the stylus pen, or the like. To be more precise, when a user performs a slide operation with a particular region of the surface deformed, the user cannot perform the slide operation smoothly.